The brain data revealed that the infant cries reduced attention to the task and triggered greater cognitive conflict processing than infant laughs."Parental instinct appears to be hardwired yet no one talks about how this instinct might include cognition," said David Haley from the University of Toronto.

The team looked at infant vocalisations - in this case, audio clips of a baby laughing or crying - and its effect on adults who completed a cognitive conflict task.

They asked participants to rapidly identify the colour of a printed word while ignoring the meaning of the word itself. Brain activity was measured using electroencephalography (EEG), which took place immediately after a two-second audio clip of an infant vocalisation.

Cognitive conflict processing is important because it controls attention - one of the most basic executive functions needed to complete a task or make a decision.

A baby's cry has been shown to cause aversion in adults but it could also be creating an adaptive response, "switching on" the cognitive control parents use in effectively responding to their child's emotional needs while also addressing other demands in everyday life, Haley added in a paper published in the journal PLOS ONE.

"If an infant's cry activates cognitive conflict in the brain, it could also be teaching parents how to focus their attention more selectively," he added.

The findings add to a growing body of research suggesting that infants occupy a privileged status in our neurobiological programming, one deeply rooted in our evolutionary past. But, as Haley noted, it also reveals an important adaptive cognitive function in the human brain.